X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=include%2Flttng%2Ftracepoint.h;h=d77a2fb298c40f99c7fd290eb48eda48d36bcae9;hb=0fd0de100bc6633e8ecf575301dc92321db32575;hp=fb635c111327e86a20a6898d364f3e175acb9a85;hpb=46c881a7d6839761e3371a93ba29e7a0202bcd03;p=lttng-ust.git

diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h
index fb635c11..d77a2fb2 100644
--- a/include/lttng/tracepoint.h
+++ b/include/lttng/tracepoint.h
@@ -23,31 +23,40 @@
  * SOFTWARE.
  */
 
+#include <stdio.h>
+#include <stdlib.h>
 #include <lttng/tracepoint-types.h>
 #include <lttng/tracepoint-rcu.h>
 #include <urcu/compiler.h>
+#include <urcu/system.h>
 #include <dlfcn.h>	/* for dlopen */
 #include <string.h>	/* for memset */
-#include <assert.h>
 #include <lttng/ust-config.h>	/* for sdt */
 #include <lttng/ust-compiler.h>
 
 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
 #define SDT_USE_VARIADIC
 #include <sys/sdt.h>
+#define LTTNG_STAP_PROBEV STAP_PROBEV
 #else
-#define STAP_PROBEV(...)
+#define LTTNG_STAP_PROBEV(...)
 #endif
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#define tracepoint_enabled(provider, name) \
+	caa_unlikely(CMM_LOAD_SHARED(__tracepoint_##provider##___##name.state))
+
+#define do_tracepoint(provider, name, ...) \
+	__tracepoint_cb_##provider##___##name(__VA_ARGS__)
+
 #define tracepoint(provider, name, ...)					    \
 	do {								    \
-		STAP_PROBEV(provider, name, ## __VA_ARGS__);		    \
-		if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
-			__tracepoint_cb_##provider##___##name(__VA_ARGS__); \
+		LTTNG_STAP_PROBEV(provider, name, ## __VA_ARGS__);	    \
+		if (tracepoint_enabled(provider, name)) 		    \
+			do_tracepoint(provider, name, __VA_ARGS__);	    \
 	} while (0)
 
 #define TP_ARGS(...)       __VA_ARGS__
@@ -144,14 +153,19 @@ extern "C" {
 #define _TP_ARGS_DATA_VAR(...)		_TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
 #define _TP_PARAMS(...)			__VA_ARGS__
 
+/*
+ * The tracepoint cb is marked always inline so we can distinguish
+ * between caller's ip addresses within the probe using the return
+ * address.
+ */
 #define _DECLARE_TRACEPOINT(_provider, _name, ...)			 		\
-extern struct tracepoint __tracepoint_##_provider##___##_name;				\
-static inline lttng_ust_notrace								\
+extern struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name;		\
+static inline __attribute__((always_inline, unused)) lttng_ust_notrace			\
 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__));		\
-static inline										\
+static											\
 void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__))		\
 {											\
-	struct tracepoint_probe *__tp_probe;						\
+	struct lttng_ust_tracepoint_probe *__tp_probe;						\
 											\
 	if (caa_unlikely(!TP_RCU_LINK_TEST()))						\
 		return;									\
@@ -160,7 +174,7 @@ void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__))		\
 	if (caa_unlikely(!__tp_probe))							\
 		goto end;								\
 	do {										\
-		void (*__tp_cb)(void) = __tp_probe->func;					\
+		void (*__tp_cb)(void) = __tp_probe->func;				\
 		void *__tp_data = __tp_probe->data;					\
 											\
 		URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb)	\
@@ -198,22 +212,19 @@ extern int __tracepoint_probe_unregister(const char *name, void (*func)(void),
  * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
  * shared across objects in a module/main executable.
  */
-struct tracepoint_dlopen {
+struct lttng_ust_tracepoint_dlopen {
 	void *liblttngust_handle;
 
-	int (*tracepoint_register_lib)(struct tracepoint * const *tracepoints_start,
+	int (*tracepoint_register_lib)(struct lttng_ust_tracepoint * const *tracepoints_start,
 		int tracepoints_count);
-	int (*tracepoint_unregister_lib)(struct tracepoint * const *tracepoints_start);
-#ifndef _LGPL_SOURCE
+	int (*tracepoint_unregister_lib)(struct lttng_ust_tracepoint * const *tracepoints_start);
 	void (*rcu_read_lock_sym_bp)(void);
 	void (*rcu_read_unlock_sym_bp)(void);
 	void *(*rcu_dereference_sym_bp)(void *p);
-#endif
 };
 
-extern struct tracepoint_dlopen tracepoint_dlopen;
-
-#if defined(TRACEPOINT_DEFINE) || defined(TRACEPOINT_CREATE_PROBES)
+extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen;
+extern struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr;
 
 /*
  * These weak symbols, the constructor, and destructor take care of
@@ -224,44 +235,109 @@ int __tracepoint_registered
 	__attribute__((weak, visibility("hidden")));
 int __tracepoint_ptrs_registered
 	__attribute__((weak, visibility("hidden")));
-struct tracepoint_dlopen tracepoint_dlopen
+struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
+	__attribute__((weak, visibility("hidden")));
+/*
+ * Deal with gcc O1 optimisation issues with weak hidden symbols. gcc
+ * 4.8 and prior does not have the same behavior for symbol scoping on
+ * 32-bit powerpc depending on the object size: symbols for objects of 8
+ * bytes or less have the same address throughout a module, whereas they
+ * have different addresses between compile units for objects larger
+ * than 8 bytes. Add this pointer indirection to ensure that the symbol
+ * scoping match that of the other weak hidden symbols found in this
+ * header.
+ */
+struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr
 	__attribute__((weak, visibility("hidden")));
 
+/*
+ * Tracepoint dynamic linkage handling (callbacks). Hidden visibility: shared
+ * across objects in a module/main executable. The callbacks are used to
+ * control and check if the destructors should be executed.
+ */
+struct lttng_ust_tracepoint_destructors_syms {
+	int *old_tracepoint_disable_destructors;
+	void (*tracepoint_disable_destructors)(void);
+	int (*tracepoint_get_destructors_state)(void);
+};
+
+extern struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms;
+extern struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr;
+
+struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms
+	__attribute__((weak, visibility("hidden")));
+struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr
+	__attribute__((weak, visibility("hidden")));
+
+static inline void tracepoint_disable_destructors(void)
+{
+	if (!tracepoint_dlopen_ptr)
+		tracepoint_dlopen_ptr = &tracepoint_dlopen;
+	if (!tracepoint_destructors_syms_ptr)
+		tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
+	if (tracepoint_dlopen_ptr->liblttngust_handle
+			&& tracepoint_destructors_syms_ptr->tracepoint_disable_destructors)
+		tracepoint_destructors_syms_ptr->tracepoint_disable_destructors();
+	*tracepoint_destructors_syms_ptr->old_tracepoint_disable_destructors = 1;
+}
+
+#ifndef _LGPL_SOURCE
+static inline void lttng_ust_notrace
+__tracepoint__init_urcu_sym(void);
+static inline void
+__tracepoint__init_urcu_sym(void)
+{
+	if (!tracepoint_dlopen_ptr)
+		tracepoint_dlopen_ptr = &tracepoint_dlopen;
+	/*
+	 * Symbols below are needed by tracepoint call sites and probe
+	 * providers.
+	 */
+	if (!tracepoint_dlopen_ptr->rcu_read_lock_sym_bp)
+		tracepoint_dlopen_ptr->rcu_read_lock_sym_bp =
+			URCU_FORCE_CAST(void (*)(void),
+				dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
+					"tp_rcu_read_lock_bp"));
+	if (!tracepoint_dlopen_ptr->rcu_read_unlock_sym_bp)
+		tracepoint_dlopen_ptr->rcu_read_unlock_sym_bp =
+			URCU_FORCE_CAST(void (*)(void),
+				dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
+					"tp_rcu_read_unlock_bp"));
+	if (!tracepoint_dlopen_ptr->rcu_dereference_sym_bp)
+		tracepoint_dlopen_ptr->rcu_dereference_sym_bp =
+			URCU_FORCE_CAST(void *(*)(void *p),
+				dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
+					"tp_rcu_dereference_sym_bp"));
+}
+#else
+static inline void lttng_ust_notrace
+__tracepoint__init_urcu_sym(void);
+static inline void
+__tracepoint__init_urcu_sym(void)
+{
+}
+#endif
+
 static void lttng_ust_notrace __attribute__((constructor))
 __tracepoints__init(void);
 static void
 __tracepoints__init(void)
 {
-	if (__tracepoint_registered++)
+	if (__tracepoint_registered++) {
+		if (!tracepoint_dlopen_ptr->liblttngust_handle)
+			return;
+		__tracepoint__init_urcu_sym();
 		return;
+	}
 
-	if (!tracepoint_dlopen.liblttngust_handle)
-		tracepoint_dlopen.liblttngust_handle =
+	if (!tracepoint_dlopen_ptr)
+		tracepoint_dlopen_ptr = &tracepoint_dlopen;
+	if (!tracepoint_dlopen_ptr->liblttngust_handle)
+		tracepoint_dlopen_ptr->liblttngust_handle =
 			dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
-	if (!tracepoint_dlopen.liblttngust_handle)
+	if (!tracepoint_dlopen_ptr->liblttngust_handle)
 		return;
-	tracepoint_dlopen.tracepoint_register_lib =
-		URCU_FORCE_CAST(int (*)(struct tracepoint * const *, int),
-				dlsym(tracepoint_dlopen.liblttngust_handle,
-					"tracepoint_register_lib"));
-	tracepoint_dlopen.tracepoint_unregister_lib =
-		URCU_FORCE_CAST(int (*)(struct tracepoint * const *),
-				dlsym(tracepoint_dlopen.liblttngust_handle,
-					"tracepoint_unregister_lib"));
-#ifndef _LGPL_SOURCE
-	tracepoint_dlopen.rcu_read_lock_sym_bp =
-		URCU_FORCE_CAST(void (*)(void),
-				dlsym(tracepoint_dlopen.liblttngust_handle,
-					"tp_rcu_read_lock_bp"));
-	tracepoint_dlopen.rcu_read_unlock_sym_bp =
-		URCU_FORCE_CAST(void (*)(void),
-				dlsym(tracepoint_dlopen.liblttngust_handle,
-					"tp_rcu_read_unlock_bp"));
-	tracepoint_dlopen.rcu_dereference_sym_bp =
-		URCU_FORCE_CAST(void *(*)(void *p),
-				dlsym(tracepoint_dlopen.liblttngust_handle,
-					"tp_rcu_dereference_sym_bp"));
-#endif
+	__tracepoint__init_urcu_sym();
 }
 
 static void lttng_ust_notrace __attribute__((destructor))
@@ -273,14 +349,46 @@ __tracepoints__destroy(void)
 
 	if (--__tracepoint_registered)
 		return;
-	if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_ptrs_registered) {
-		ret = dlclose(tracepoint_dlopen.liblttngust_handle);
-		assert(!ret);
-		memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
+	if (!tracepoint_dlopen_ptr)
+		tracepoint_dlopen_ptr = &tracepoint_dlopen;
+	if (!tracepoint_destructors_syms_ptr)
+		tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
+	if (!tracepoint_dlopen_ptr->liblttngust_handle)
+		return;
+	if (__tracepoint_ptrs_registered)
+		return;
+	/*
+	 * Lookup if destructors must be executed using the new method.
+	 */
+	if (tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
+		&& !tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()) {
+		/*
+		 * The tracepoint_get_destructors_state symbol was found with
+		 * dlsym but its returned value is 0 meaning that destructors
+		 * must not be executed.
+		 */
+		return;
+	}
+	/*
+	 * Lookup if destructors must be executed using the old method.
+	 */
+	if (tracepoint_destructors_syms_ptr->old_tracepoint_disable_destructors
+		&& *tracepoint_destructors_syms_ptr->old_tracepoint_disable_destructors) {
+		/*
+		 * The old_tracepoint_disable_destructors symbol was found with
+		 * dlsym but its value is 1 meaning that destructors must not
+		 * be executed.
+		 */
+		return;
 	}
-}
 
-#endif
+	ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
+	if (ret) {
+		fprintf(stderr, "Error (%d) in dlclose\n", ret);
+		abort();
+	}
+	memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
+}
 
 #ifdef TRACEPOINT_DEFINE
 
@@ -289,9 +397,9 @@ __tracepoints__destroy(void)
  * registering only _one_ instance of the tracepoints per shared-ojbect
  * (or for the whole main program).
  */
-extern struct tracepoint * const __start___tracepoints_ptrs[]
+extern struct lttng_ust_tracepoint * const __start___tracepoints_ptrs[]
 	__attribute__((weak, visibility("hidden")));
-extern struct tracepoint * const __stop___tracepoints_ptrs[]
+extern struct lttng_ust_tracepoint * const __stop___tracepoints_ptrs[]
 	__attribute__((weak, visibility("hidden")));
 
 /*
@@ -321,7 +429,7 @@ extern struct tracepoint * const __stop___tracepoints_ptrs[]
 	static const char __tp_strtab_##_provider##___##_name[]			\
 		__attribute__((section("__tracepoints_strings"))) =		\
 			#_provider ":" #_name;					\
-	struct tracepoint __tracepoint_##_provider##___##_name			\
+	struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name	\
 		__attribute__((section("__tracepoints"))) =			\
 		{								\
 			__tp_strtab_##_provider##___##_name,			\
@@ -329,8 +437,10 @@ extern struct tracepoint * const __stop___tracepoints_ptrs[]
 			NULL,							\
 			_TRACEPOINT_UNDEFINED_REF(_provider), 			\
 			_TP_EXTRACT_STRING(_args),				\
+			{ },							\
 		};								\
-	static struct tracepoint * __tracepoint_ptr_##_provider##___##_name	\
+	static struct lttng_ust_tracepoint *					\
+		__tracepoint_ptr_##_provider##___##_name			\
 		__attribute__((used, section("__tracepoints_ptrs"))) =		\
 			&__tracepoint_##_provider##___##_name;
 
@@ -341,14 +451,41 @@ __tracepoints__ptrs_init(void)
 {
 	if (__tracepoint_ptrs_registered++)
 		return;
-	if (!tracepoint_dlopen.liblttngust_handle)
-		tracepoint_dlopen.liblttngust_handle =
+	if (!tracepoint_dlopen_ptr)
+		tracepoint_dlopen_ptr = &tracepoint_dlopen;
+	if (!tracepoint_dlopen_ptr->liblttngust_handle)
+		tracepoint_dlopen_ptr->liblttngust_handle =
 			dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
-	if (!tracepoint_dlopen.liblttngust_handle)
+	if (!tracepoint_dlopen_ptr->liblttngust_handle)
 		return;
-	tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs,
+	if (!tracepoint_destructors_syms_ptr)
+		tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
+	tracepoint_dlopen_ptr->tracepoint_register_lib =
+		URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int),
+				dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
+					"tracepoint_register_lib"));
+	tracepoint_dlopen_ptr->tracepoint_unregister_lib =
+		URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *),
+				dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
+					"tracepoint_unregister_lib"));
+	tracepoint_destructors_syms_ptr->old_tracepoint_disable_destructors =
+		URCU_FORCE_CAST(int *,
+				dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
+					"__tracepoints__disable_destructors"));
+	tracepoint_destructors_syms_ptr->tracepoint_disable_destructors =
+		URCU_FORCE_CAST(void (*)(void),
+				dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
+					"tp_disable_destructors"));
+	tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state =
+		URCU_FORCE_CAST(int (*)(void),
+				dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
+					"tp_get_destructors_state"));
+	__tracepoint__init_urcu_sym();
+	if (tracepoint_dlopen_ptr->tracepoint_register_lib) {
+		tracepoint_dlopen_ptr->tracepoint_register_lib(__start___tracepoints_ptrs,
 				__stop___tracepoints_ptrs -
 				__start___tracepoints_ptrs);
+	}
 }
 
 static void lttng_ust_notrace __attribute__((destructor))
@@ -360,12 +497,22 @@ __tracepoints__ptrs_destroy(void)
 
 	if (--__tracepoint_ptrs_registered)
 		return;
-	if (tracepoint_dlopen.tracepoint_unregister_lib)
-		tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
-	if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_registered) {
-		ret = dlclose(tracepoint_dlopen.liblttngust_handle);
-		assert(!ret);
-		memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
+	if (!tracepoint_dlopen_ptr)
+		tracepoint_dlopen_ptr = &tracepoint_dlopen;
+	if (!tracepoint_destructors_syms_ptr)
+		tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
+	if (tracepoint_dlopen_ptr->tracepoint_unregister_lib)
+		tracepoint_dlopen_ptr->tracepoint_unregister_lib(__start___tracepoints_ptrs);
+	if (tracepoint_dlopen_ptr->liblttngust_handle
+			&& tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
+			&& tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()
+			&& !__tracepoint_ptrs_registered) {
+		ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
+		if (ret) {
+			fprintf(stderr, "Error (%d) in dlclose\n", ret);
+			abort();
+		}
+		memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
 	}
 }
 
@@ -383,6 +530,50 @@ __tracepoints__ptrs_destroy(void)
 
 /* The following declarations must be outside re-inclusion protection. */
 
+#ifndef TRACEPOINT_ENUM
+
+/*
+ * Tracepoint Enumerations
+ *
+ * The enumeration is a mapping between an integer, or range of integers, and
+ * a string. It can be used to have a more compact trace in cases where the
+ * possible values for a field are limited:
+ *
+ * An example:
+ *
+ * TRACEPOINT_ENUM(someproject_component, enumname,
+ *	TP_ENUM_VALUES(
+ *		ctf_enum_value("even", 0)
+ *		ctf_enum_value("uneven", 1)
+ *		ctf_enum_range("twoto4", 2, 4)
+ *		ctf_enum_value("five", 5)
+ *	)
+ * )
+ *
+ * Where "someproject_component" is the name of the component this enumeration
+ * belongs to and "enumname" identifies this enumeration. Inside the
+ * TP_ENUM_VALUES macro is the actual mapping. Each string value can map
+ * to either a single value with ctf_enum_value or a range of values
+ * with ctf_enum_range.
+ *
+ * Enumeration ranges may overlap, but the behavior is implementation-defined,
+ * each trace reader will handle overlapping as it wishes.
+ *
+ * That enumeration can then be used in a field inside the TP_FIELD macro using
+ * the following line:
+ *
+ * ctf_enum(someproject_component, enumname, enumtype, enumfield, enumval)
+ *
+ * Where "someproject_component" and "enumname" match those in the
+ * TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
+ * backing the enumeration, "enumfield" is the name of the field and
+ * "enumval" is the value.
+ */
+
+#define TRACEPOINT_ENUM(provider, name, values)
+
+#endif /* #ifndef TRACEPOINT_ENUM */
+
 #ifndef TRACEPOINT_EVENT
 
 /*
@@ -406,6 +597,9 @@ __tracepoints__ptrs_destroy(void)
  *         * Integer, printed with 0x base 16 * 
  *         ctf_integer_hex(unsigned long, field_d, arg1)
  *
+ *         * Enumeration *
+ *         ctf_enum(someproject_component, enum_name, int, field_e, arg0)
+ *
  *         * Array Sequence, printed as UTF8-encoded array of bytes * 
  *         ctf_array_text(char, field_b, string, FIXED_LEN)
  *         ctf_sequence_text(char, field_c, string, size_t, strlen)
@@ -533,7 +727,7 @@ __tracepoints__ptrs_destroy(void)
  * debug information with line-level scope (TRACEPOINT_EVENT default)
  *
  * TRACE_DEBUG           14
- * debug-level message (trace_printf default)
+ * debug-level message
  *
  * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
  * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given